1. Field of the Invention
The present invention relates to medical devices, and more specifically relates to clamping devices used to dispense surgical fasteners into soft media.
2. Description of the Related Art
Hernia is a condition in which a small loop of bowel or intestine protrudes through a weak place or defect within the abdominal muscle wall or groin of a patient. Hernias may result from a congenital defect, or may be caused by straining or lifting heavy objects. A hernia may leave the patient with an unsightly bulge of intestinal tissue protruding through the defect, and may cause pain, reduced lifting abilities, impaction of the bowel, or possibly other complications if the flow of blood is cut off to the protruding tissue.
Surgery may be required to repair a hernia. During a hernia repair procedure, the defect is accessed and carefully examined through an open incision or endoscopically through a trocar. In either case, careful examination is required due to the delicate network of vessels and nerves that surround the area of the defect. As such, surgeons must conduct hernia repair procedures with great skill and caution.
Repairing a hernia may involve closing the defect with sutures or fasteners. The hernia repair procedure may also involve placing a surgical prosthetic device such as a mesh patch over the open defect, and attaching the mesh patch to the abdominal wall or inguinal floor with conventional sutures or surgical fasteners. The mesh patch acts as a barrier and prevents expulsion of the bowel through the defect.
One type of common hernia is a ventral hernia. This type of hernia typically occurs in the abdominal wall and may be caused by a prior incision or puncture, or by an area of tissue weakness that is stressed. There are several repair procedures that can be employed by the surgeon, depending upon the individual characteristics of the patient and the nature of the hernia. In an Intra-peritoneal onlay mesh (IPOM) repair technique, a specific mesh is used with a flat repair layer fused to a fixation layer around the perimeter. The fixation layer has an opening to facilitate the insertion of a fixation device between the layers. During an IPOM repair, an incision is made directly over the site of the ventral hernia. The mesh is rolled and inserted through the incision and hernia into the pre-peritoneal space. The mesh is then centrally positioned underneath the hernia with the repair layer downward, facing the viscera. Stay sutures may be placed to position the mesh. Then, a fixation device is used to secure the fixation layer to the abdominal wall. Fixation of the top fixation layer will also secure the bottom repair layer as well. After the mesh is secured and is flat against the abdominal wall, the hernia defect and the skin incision may be closed using sutures.
At present, there are a variety of surgical instruments and fasteners used for attaching mesh patches to tissue. One of the earliest types of surgical instruments used is a surgical stapler, whereby a stack of staples are contained within a stapling cartridge, and are sequentially advanced within the instrument by a spring mechanism. A secondary mechanism is employed to separate the distal-most staple from the stack, to hold the remainder of the staples in the stack, and to feed the distal-most staple into the staple forming mechanism. Feeding mechanisms of this type are found in U.S. Pat. Nos. 5,470,010 and 5,582,616, to Rothfuss et al.
Another hernia mesh attachment instrument uses a helical wire fastener that resembles a small section of a spring. Multiple helical wire fasteners are stored serially within a 5 mm shaft, and are corkscrewed into tissue. A load spring is used to feed the plurality of helical fasteners distally within the shaft. A protrusion extends into the shaft to prevent the ejection of the stack of fasteners by the load spring to permit passage of a rotating fastener. Instruments and fasteners of these types are found in U.S. Pat. Nos. 5,582,616 and 5,810,882 to Bolduc et al., and U.S. Pat. No. 5,830,221 to Stein et al.
Other surgical fasteners used for hernia mesh attachment utilize either a reloadable single shot instrument or a rotary magazine that holds a small number of fasteners. These types of surgical fastening instruments are disclosed in U.S. Pat. Nos. 5,203,864 and 5,290,297 to Edward Phillips. These instruments have not gained acceptance by the surgical community, possibly due to their single shot capabilities and the large size of the rotary magazine, which can restrict use of such an instrument to an open procedure.
U.S. Pat. Nos. 5,601,573; 5,833,700; and 5,921,997 to Fogelberg et al. teach a clip applier with a feeding mechanism that utilizes a reciprocating feed bar to feed a stack of clips. A feeder shoe operably engages with and moves with the distally moving feed bar and slidingly engages with the proximally moving feed bar. The feeder shoe pushes the stack of clips distally with the distally moving feed bar and remains stationary relative to the proximally moving feed bar. A valving mechanism separates the distal-most clip from the stack holds the stack stationary as the distal-most clip may be dispensed onto a vessel.
U.S. Pat. No. 4,325,376 to Klieman et al teaches a clip applier that stores a stack of clips in a serial fashion within a clip magazine. The proximal-most clip is pushed distally by a pawl that is ratcheted distally by a reciprocating member with each actuation of the instrument. As the pawl ratchets distally, it pushes the stack of clips distally.
Commonly assigned U.S. Patent Application Publication No. 2002/0068947, the disclosure of which is hereby incorporated by reference herein, teaches a device for delivering a plurality of individual surgical fasteners. In one embodiment, the delivery device includes a drive mechanism having distal and proximal ends. The drive mechanism has a moving member and a fixed opposing member, whereby the moving member is moveable proximally and distally with respect to the delivery device. The moving member has a sharpened distal end for piercing tissue. The device includes at least one surgical fastener located between the first and the second members. Each of the surgical fasteners has a proximal end and a distal end. The device also has an actuator having at least two sequential positions. A first position for advancing the moving member distally and piercing tissue, and a second position for moving the moving member proximally, thereby deploying the distal end of the fastener.
The above-described instruments dispense the surgical fasteners along an axis that is parallel with the longitudinal axis of the instrument. In some instances, this dispensing angle makes it difficult for medical personnel to insert surgical fasteners along axes that are normal to the surface of the tissue receiving the fasteners. Moreover, conventional instruments require the operator to use his or her hand as a backup for providing an opposing force on the tissue receiving the fasteners. This often results in medical personnel being pricked by the sharp ends of the surgical fasteners.
In view of the above-noted deficiencies, there remains a need for improved systems, devices and methods for more economically and efficiently securing prosthetic devices using surgical fasteners. In particular, there remains a need for instruments that easily dispense surgical fasteners at angles that are perpendicular to the surface of the tissue receiving the fasteners. There also remains a need for instruments that do not require medical personnel to use a second hand as an anvil for the tissue receiving the surgical fastener. There also remains a need for an instrument that dispenses a surgical fastener when sufficient compression has been applied and that provides an indication that a predetermined compression level has been attained. There also remains a need for a device that provides a clear map on the patient's outer skin surface that indicates where the surgical fasteners have been inserted, as well as the total number of surgical fasteners that have been dispensed into tissue.